You should put the code posted by Alberto in the Shown and SelectionChanged events.
It is a very simple project, just this:
soccerball is a transparent PNG
ImageView1- Behavior - Picture - soccerball
ListBox1 Open():
For i As Integer = 0 To 5
Me.AddRow "This is transparent"
Next
ListBox1 SelectionChanged():
Dim js As String
js = js + "var tbl = document.getElementById('"+ ListBox1.controlID +"_rows');"
js = js + "for (i = 0; i < tbl.rows.length-1; i=i+2) { tbl.rows[i].style.backgroundColor='rgba(255,255,255,0.7)'; tbl.rows[i+1].style.backgroundColor='rgba(237,243,254,0.7)';}"
Self.ExecuteJavaScript(js)
ListBox1 Shown():
Dim js As String
js = js + "var tbl = document.getElementById('"+ ListBox1.controlID +"_rows');"
js = js + "for (i = 0; i < tbl.rows.length-1; i=i+2) { tbl.rows[i].style.backgroundColor='rgba(255,255,255,0.7)'; tbl.rows[i+1].style.backgroundColor='rgba(237,243,254,0.7)';}"
Self.ExecuteJavaScript(js)
StyleTransparent - Background color: Red 235, Green 0, Blue 0, Opacity 129
Note: ImageView1 z-order is behind ListBox1
Edit: ListBox1 - Inspector - Styles - Style: StyleTransparent